The present invention relates to a method of investigating the suitability of a material as a medicament for mammals, particularly humans. The invention further relates to a kit with which such a method can be put into practice.
The development of new medicaments takes a total of 10 to 12 years on average. A large part of this time is taken up initially in targeting a material which may be suitable for a specific indication. The number of initially screened substances frequently runs into hundreds of thousands. There is therefore a particular need for a simple and rapid test method by which the substances to be examined can basically be categorized as suitable or unsuitable, but no methods are currently known which are capable of predicting a possible efficacy in humans (or other mammals) with a high degree of reliability. Animal models are of course available for this purpose, but they are either unreliable and/or very expensive in terms of their predictive value. Moreover, conventional animal models are increasingly being generally rejected because they cause the animals (for example dogs and monkeys) to suffer. On the other hand, animal models are normally required to have a great similarity to the human organism so as to guarantee some likelihood that the knowledge gained from the animal experiments will be applicable to humans.
There is a particular need for an animal model which has a high predictive value and which can either replace conventional animal models or at least reduce the scale of experiments on higher organisms (such as mammals). This need is particularly relevant in the search for drugs which influence the human perception of pain, e.g. analgesics and sedatives.
The present invention goes back to the discovery that nematodes (threadworms) exhibit a retraction reflex to a local thermal stimulus and that this reflex can be influenced by active substances that affect the human perception of pain. The present invention is based on the knowledge that certain threadworms react in a defined way to locally applied thermal stimuli and that the reflex to this stimulus allows a prediction to be made as regards the effect of a particular material on the sensation of pain in humans (including mammals).